An Android app developer in America has posted a video showing what he claims is 'conclusive proof' that 'Carrier IQ' software installed by manufacturers of many US phones record the way those phone are used in real time, as well as their geographic locations.

Carrier IQ has claimed that the software only tracks information for the benefit of users, not for any spying purposes, and that it is “counting and summarising” information rather than recording it.

However, in a YouTube video posted on Monday, the developer, Trevor Eckhart, did a “factory reset” on his Android phone, returning it to the condition in which it is shipped to customers, and linked it to a computer screen which allegedly displayed what the Carrier IQ software was tracking.

The demonstration showed that the software read every keystroke put into the phone, as well as every text message sent to it. It also appeared to log location data, and transmit this to Carrier IQ.

Mr Eckhart, claims it is used by manufacturers of phones that use Google's Android operating system, as well as some BlackBerry and Nokia handsets. It is not thought to be used in Apple’s iPhones.

It is not known if Carrier IQ is in use in Europe, where it might present a serious breach of the Data Protection laws.

A source at a leading mobile operator said his company didn't install it but that he had been investigating whether UK manufacturers had done so and “couldn’t give a definitive answer”.

Carrier IQ said in a statement that it “assists operators and device manufacturers in delivering high quality products and services to their customers … by counting and measuring operational information in mobile devices – feature phones, smartphones and tablets.

“The information gathered by Carrier IQ is done so for the exclusive use of that customer, and Carrier IQ does not sell personal subscriber information to third parties,” it added.

Carrier IQ would not return requests for further comment, but according to US reports it has issued Mr Eckhart with an order to take down its video. There is no suggestion that Google has authorised the use of the Carrier IQ technology.